1. Field of Invention
The present invention relates to an LED lamp. More particularly, the present invention relates to a color temperature adjustable LED lamp having a 3-way switch.
2. Description of Related Art
For a fluorescent tube the wavelength of the light emitted by a filament can be changed through phosphor powders. The existing color temperature adjustable lighting lamps mostly use two kinds of fluorescent tubes with different color temperatures to achieve a mixed light. For example, two kinds of fluorescent tubes are arranged in the same lighting lamp, wherein the color temperature of one fluorescent tube is 2600 k (warm white light), and the color temperature of the other fluorescent tube is 5600 k (cold white light). By operating the switch, a fluorescent tube to emit light can be selected. When the two kinds of fluorescent tubes with different color temperatures operate at the same time, a light source with a color temperature between 2600 k and 5600 k can be obtained. However, due to the large volume of the fluorescent tube, the volume of this color temperature adjustable lighting lamp is hard to be reduced. Furthermore, since the two kinds of fluorescent tubes need to be turned on at the same time for mixing lights, the lighting illumination at this time is twice of the lighting illumination generated when a fluorescent tube with a single color temperature is used. This may easily discomfort users.
An LED has the properties of high durability, long lifetime, light weight, low power consumption and so on, which is a desired lighting light source in the new times. Particularly under the current situation that the energy cost is gradually increasing, the LED gets attention and is used by the industry, to replace other light-emitting components with higher power consumptions.
Applying an LED to lighting lamps can reduce the volume of the lighting lamps, but the subsequent topic to be solved is how to make a further utilization of the LED as a light source and design the LED as a color temperature adjustable lamp.